AUBURN, June 1—Some nutritionists believe we would all be a lot healthier if we ate more like our paleolithic ancestors.

In one respect, they’re right. Prehistoric diets, after all, were almost entirely free of saturated fat, sodium and sugar – factors associated with the rising levels of obesity, heart disease and diabetes commonplace in our own century.

In fact, that is why many nutritionists believe these ancient diets deserve a closer look, if only to establish a benchmark for healthier eating today.

“We need to look at this diet and determine how we can get our modern diet at least back to some semblance of it,” says Dr. Robert Keith, an Alabama Cooperative Extension System nutritionist, “but we?re never going to be able to follow the prehistoric diet completely.”

One major difference between the paleolithic and modern American diet involves the amount of protein consumed by our distant ancestors. While standard recommendations today emphasize the need to restrict protein intake to between 10 and 15 percent of overall calories, researchers believe some paleolithic humans derived up to 60 percent of their calories from protein.

But there is one important difference between now and then. Whereas many of the protein sources we consume tend to be high in saturated fats, most of the protein consumed by our ancient forebears tended to be extremely low in saturated fats.

“Studying these ancient diets, you’ll see that they were high in protein, but they certainly weren’t comparable to the high-protein diets some diet gurus recommend today,” Keith says. “Yes, they were high in protein, but protein derived from very lean meat.”

“Our leanest meat and pork products wouldn’t compare with what they ate. Probably the closest thing we have would be chicken or turkey without the skin.”

Also, the small amount of fat in the prehistoric diet contained a high proportion of unsaturated fat, such as omega-3 fatty acids, which are now believed to provide a heart-disease safeguard, Keith says.

In temperate and tropical regions where fruits and vegetables were readily available, paleolithic humans also consumed prodigious amounts of fiber – between 100 and 150 grams a day. By enhancing the frequency of bowel movements, this may have aided in the quick elimination of carcinogenic substances from the intestinal tract.

Since bovine animals had not yet been domesticated, early humans derived almost all their calcium from plant foods – a fact that, by 21st century standards, reflected an incredible amount of plant consumption.

“Today, the only way to forgo dairy products entirely would be by eating between 10 and 12 servings a day of calcium-rich vegetables such as broccoli or spinach,” Keith says. “But since most of us simply aren’t willing to do that, there is no other way to get our calcium intake other than from a supplement.”

Today, humanity depends on only about 100 crops for 90 percent of the food supply. Our paleolithic ancestors, by contrast, consumed a much wider variety of plant micronutrients derived from a plant supply that was equally as diverse.

Wild grains, when available, were a staple of the paleolithic diet. Chock-full of nutrients, they were a far cry from the highly processed, nutritionally puny white bread common today.

Sodium, a staple of the modern diet, also was an extremely rare ingredient in paleolithic diets.

“Sodium generally is a dietary substance that is added to food,” Keith says. “Since sodium is only found in small amounts in fresh foods, it’s likely our paleolithic forebears consumed very little of this mineral each day.”

The absence of antibiotics, coupled with the accident-prone nature of the hunter-gathering lifestyle, meant very few paleolithic humans lived to age 60 – only about 9 in 100, by some estimates. Nevertheless, those who survived likely were impressive physical specimens, free of heart disease, hypertension and diabetes that plague so many moderns in old age.

So what can the paleolithic diet teach us about our own lifestyle?

First, Keith says, the insight researchers have gained from studying paleolithic diets shouldn’t be interpreted as an invitation to abandon all the conveniences of the modern diet.

Processed foods, after all, are a fact of life – the earth’s 6 billion people couldn’t survive without them. Even so, that doesn’t mean there is not a lot to be gained by adopting some aspects of the paleolithic diet.

Incorporating a high-fiber diet, rich in fruits and vegetables (especially green leafy vegetables) would be a good place to start, Keith says. Another step would be to replace highly processed white bread with unrefined products such as stone-ground, whole wheat bread.

“As a general rule, the darker the color and heavier the bread, the less processed it tends to be,” Keith says.

Raisin Bran, whole and shredded wheat products also are good alternatives, he says.

Another good place to start would be substituting meat and pork with more baked and broiled poultry and marine products, Keith adds.